<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>
<body>
    <div onclick="alert('hello js')"> 这是一个div </div>
    <script>
    function add(){
        let result = 0;
        for(let elem of arguments){
            result += elem;
        }
        return result;
    }
    console.log(add(10));
    console.log(add(10,20));
    console.log(add(10,20,30));

    </script>
</body>
</html>